Flux cored tubular electrode for gas shielded electric-arc welding

ABSTRACT

A continuous electrode for shielded-gas welding and building-up of steels consisting of a powdery core in a steel envelope, the core comprising taken in the following per cent by weight: FLUORITE CONCENTRATE15-26MARBLE5.0-10FERROMANGANESE4.56.5FERROSILICON1.0 -3.5ALUMINA2.0-6.0MANGANESE ORE0.5-1.5 THE BALANCE BEING IRON POWDER. The electrode having a core composition according to the present invention features good welding and technological characteristics and provides for high mechanical properties of the weld joint metal.

Elite States Patent Pokhodnya et a1.

FLUX CORED TUBULAR ELECTRODE FOR GAS SHIELDED ELECTRIC-ARC WELDING Inventors: Igor Konstantinovich Pokhodnya; Vladimir Nikolaevich Golovko, both of Kiev, U.S.S.R.

Institut Elektrosvarki irneni E. O. Patrona Akademii Nauk Ukrainskoi SSR, Kiev, U.S.S.R.

Filed: July 8, 1971 Appl. No.: 160,918

Assignee:

US. Cl ..219/146, 219/137 Int. Cl. ..B23k 35/22 Field of Search ..2l9/l45, 146, 73,

References Cited UNITED STATES PATENTS 7/1971 Pokhodnya .....219/l46 11/1970 Duttera et al. ...2l9/l46 4/ 1965 Danhier ..219/146 May 22, 197a Primary Examiner-J. V. Truhe Assistant Examiner-George A. Montanye Attorney-Eric H. Waters, John G. Schwartz and J. Harold Nissen [5 7] ABSTRACT A continuous electrode for shielded-gas welding and building-up of steels consisting of a powdery core in a steel envelope, the core comprising taken in the following per cent by weight:

fluorite concentrate TG 15-26 marble 5.0-l0 ferromanganese 4.5-6.5 ferrosilicon 1.0-3.5 alumina 2.0-6.0 manganese ore 0.5-1.5

the balance being iron powder.

2 Claims, No Drawings The present invention relates to electrode materials for electric-arc welding and, more particularly, the invention relates to continuous electrodes for welding with forced and free formation of a weld joint in a shielding gas atmosphere, preferably in carbon dioxide gas.

This invention can most effectively be used in automatic and semi-automatic welding with a forced and free formation of a weld joint in a shielding gas atmosphere.

Known in the art are continuous electrodes for shielded-gas welding. The best characteristics are exhibited by electrodes whose core contains fluorite concentrate, marble, ferromanganese, ferrosilicon iron powder.

For example, a flux-cored welding electrode is known the core of which contains -25 percent of fluorite concentrate, 1.5- percent of marble, 5-10 percent of ferromanganese, 2-8 percent of ferrosilicon, 60 percent of iron powder (of. British Pat. No. 1,079,710, cl.B3k).

However, these known flux-cored electrodes have poor welding and technological characteristics and inadequate mechanical properties of the metal of the weld joint.

The specific object of the invention is to provide such a continuous electrode for shielded-gas welding, in which the composition of the core would ensure good welding and technological characteristics and mechanical properties of the weld joint metal within a wide range of operating conditions as well as high efficiency of building-up.

This object is attained by providing a continuous The present invention will be apparent from the following examples of carrying out the invention.

The continuous electrode for shielded-gas welding of steels with forced and free formation of a weld joint ac- 5 cording to the invention consists of a powder core in a steel sheath comprising the following components taken in percent by weight of the core:

fluorite concentrate -26 marble 5-10 ferromanganese 4.5-6.5 ferrosilicon 1-3.5 alumina 2-6 manganese ore 0.5-1 5 EXAMPLE 1 A continuous flux-cored electrode having a diameter of 2.5 mm, in which the steel sheath comprises 70 percent of the electrode by weight and the core has the following composition (wt.%):

fluorite concentrate 1S marble 5 ferromanganese 4.5 ferrosilicon 1.0 alumina 2.0 manganese ore 0.5 iron powder 72.0

This electrode provides for good formation of the weld joint metal and allows the slag to be easily removed. The process of welding is characterized by good stability, and the losses of splashed metal are insignificant as seen from the data given below.

Instanta- Specific Impact strength in kg.m/ Welding Welding neous elongncm? at- Position of current, voltage, strength, tion,

Type of welding welding a. v. kgJmm. percent +20 0. -40 C. 60 0.

Free formation Downhand. 350- 100 28-32 50. 3-51. 5 29. 2-3l. 2 20. 2-23. 4 10. 2-12. 4

Forced formation. Vertical. 350-400 28-30 52. 5-53. 5 29. 4-32. 5 .5-17. 2 8. 5-10. 5

electrode for a shielded-gas welding process which con- EXAMPLE 2 sists of a powdery core in a steel sheath containing fluorite concentrate, marble, ferromanganese, ferrosilicon, iron powder, wherein, according to the invention, the powder core, besides the above-mentioned components taken in per cent by weight;

the balance being iron powder.

The electrode having a core composition according to the present invention features good welding and technological characteristics and provides for high mechanical properties of the weld joint metal.

A continuous flux-cored electrode having a diameter of 3.0 mm, in which the steel sheath comprises 70 percent of the total weight of the electrode, the core containing (percent by weight):

fluorite concentrate marble ferromanganese ferrosilicon alumina manganese ore iron powder (AQPPJQQN 3 00mm case the mechanical properties of the weld joint metal and of the joint itself are at a high level as shown in the table below.

Instanta- Specific Impact strength in kg.m/ Welding Welding neous elongacm. a Position of current, voltage, strength, tion, Type of welding welding a. v. kg./mm. percent +20 C. -40 C. 60 0.

Free formation l)ownhand 350-400 28-32 51.5-52.3 29. 4-30. 5 20. 6-23. 5 10. 2-11. 5 Forced formation- Vertical. 350-400 28-30 53. 2-54. 5 29. 531. 2 15. 12-18. 5 10. 5-12. 5

3 4 EXAMPLE 3 of vertical, inclined and horizontal joints made by A flux-cored electrode having a diameter of 3.0 mm means offorced formation as as good formation of in which the steel sheath comprises 70 percent of the Jomts m by means offfee formauon- The f 5 total weight of the electrode and the core contains made with the help of electrode Offer 3 g T6815- tance to hot cracks, have a low content of gases, and

feature high mechanical characteristics.

fluorite concentrate 28 wh t we l i i bl 1 gii g 65 1. A continuous electrode for shielded-gas welding 33:2 :3 and built-up welding of steel consisting of a steel sheath manganese ore 1:5 with a powder core comprising in percent of the core iron powder 46.5 i h The electrode provides for high efficiency and stabilfluorite concentrate 1546 ity of the building-up process, good technological propmarble 5.0 10

erties and high mechanical characteristics of the weld l5 alumna manganese ore 0.5-1.5

oint. The results of the tests are given in the table beferromanganese low. ferrosilicon 1.0-3.5

Instanta- Specific Impact strength in kg.m/

Welding Welding neous elongnem. at- Position of current, voltage, strength, tion, Type of welding welding 21. v. kgJmm. percent C. -40 C. 60" C.

Free lormationflun D0wnhand 350-400 28-32 52. 5-54. 2 27. 0-20. 2 18 2-22. 0 10 5-11 7 Forced formation Vertical. 350-400 28-30 53. 5-54. 5 25. 4-28. 3 14 3-16. 2 8. 4-9 2 The above examples well characterize the advantages the balance being iron powder. of the electrode of the invention.

The claimed electrode is designed for welding by means of reverse-polarity direct current in a shielding 30 gas atmosphere (substantially in carbon dioxide gas). The electrode provides for extremely good formation 2. A continuous electrode as claimed in claim 1 wherein the core constitutes 30 percent by weight of the electrode. 

2. A continuous electrode as claimed in claim 1 wherein the core constitutes 30 percent by weight of the electrode. 